This week in science

摘要

Quantitative trait loci (QTLs) are genetic loci correlated with a typically additive phenotypic trait such as height or color. In Soay sheep, dark coat color is associated with large body size, which is heritable and positively correlated with fitness. Through mapping of the region associated with the loci determining coat color, Gratten et al. (p. 318) detail the linkage of several causal mutations within a small genomic region within a free-living sheep population. A strong correlation was found between coat color and weight, but these relations showed antagonistic effects between body size and lifetime fitness. This study provides empirical support for the role of a negative genetic correlation in the evolutionary dynamics of a natural population.